Background: An increasing body of research considers the immunological effects of major depression. It remains an open question, whether depression itself acts in an immunomodulatory fashion or whether other factors related to depression result in these immunological effects. Regardless, major depression is often the result of early life stress, the implications of which are not satisfactorily understood. Subjects and methods: Early life stress was retrospectively evaluated in 25 depressed inpatients via the CTQ (Childhood Trauma Questionnaire). Its impact on immunological biomarkers (fibrinogen, SAA, CRP, adiponectin, TNF-alpha, resistin, and sE-selectin) in adulthood was assessed via multiple regression analyses. Parental bonding was assessed via the PBI (Parental bonding questionnaire), severity of depression with the HDRS-17 (Hamilton-Depression-Rating Scale). Results: Nearly all patients had experienced a parental style of affectionless control. Physical neglect significantly predicted fibrinogen levels (R-2=0.42, adjusted R-2=0.27, beta=0.56, p=0.04). Severity of depression was not associated with immune markers. Conclusion: Childhood maltreatment was linked to fibrinogen levels in our sample. Thus, inflammation may be an important mechanism mediating the adverse effects of early life stress on adult health in patients with major depression.